I do not see how they could be the L. noctiluca, as he states.
Noctiluca flashes on stimulation of any kind, even the slightest agitation causing a brilliant emission of light.
Noctiluca miliaris, acted upon by iodine solution, showing the protoplasm shrunk away from the structureless pellicle.
The exchange of life-elements between two individuals is well illustrated in the case of the infusorian Noctiluca.
Two new individuals are thus formed, and each Noctiluca has absorbed half of the other.
Probably the Noctiluca is not rivalled in this respect even by miscroscopic unicellular alg which compose the "red snow."
Both in its nature and immature forms, Lampyris noctiluca plays a useful part in the economy of Nature.